Underreamer



March 13, 1928. 1,662,138

la.v F. WALDRON UNDERREAMER Patented Mar. 13, 1928. i

UNITED srA'rss maries BENJAMIN FRANKLIN WALDRON, OF DUNCAN, OKLAHOMA.

UNDERREAIYIER.

Application filed Apri1-28, 192,5. Serial No. 26,494.

The present invention has reference 'to devices known as underreamers employed in connection with well drilling machinery to underream or cut the bore holed below the well casing to permit the well casing to pass into the bore hole.

An important object of the invention is to provide. a. device of this character including pivoted jaws adapted to be expanded after they have passed the lower end of the well casing or lining, to underream the borehole. y

A still further object ofthe invention is to provide means whereby the nnderreamer may beeasily and readily withdrawn from its position within the well casing or lining after it has accomplished its purpose.

With the foregoing and other objects in view which will appear as the description proceeds, the invention resides in the combination and arrangement of parts. and in the details of construction hereinafter described and claimed, it being understood that changes in the precise embodiment of` the invention herein disclosed, may be made within the scope of what is claimed, without departing from the spirit of the invention.

Referring -to the drawings:

Figure 1 is a longitudinal sectional view through an underreamer constructed in accordance with ythe presentv invention, yt-he lower portion of the reamer being shown in elevation. n

Figure 2 is a sectional view taken on line 2-2 of Figure 4. y Y l Figure 3 is a sectional view taken online 3-3 of Figure 1.

Figure 4 is an enlarged sectional view of the lower portion of the underreamer.

Figure 5 is afragmental sectional view of a portion of the underreamer in its inactive position.

Referring to the drawings in detail, the reference character 5 indicates thewell casing or lining through which the underreamer is passed when moved to its active position. i

The reference character 6 indicates the body portion or stock of the reamer which is hollowed out t-o accommodate the coupling 7 which is provided with a tapered threaded opening 8 at its upper end to accommodate the threaded extension 9 of the rod section if* l() positioned thereabove.

The coupling 7 is formed with a longitudinal bore the upper extremity of which `being threaded to accommodate the threaded portion 11 of the rod 12, the lowerend of the rod 12'being provided with an enlargement l'formed with a shoulder 14 piovidinga seat for the lower extremity of the coiled spring 15 that acts to normally urge the jaws and jaw supporting rod, to be hereinafter more fully described, downwardly.

The body.. portion 6 is formed with a central enlarged bore 16 in which the coiled spring 15 is positioned, there being provided a shoulder 17 at the upper end of the enlarged bore 1G against which the upper end of' the coiled spring 15 abuts. Thus it will tensions 2O provided with cut out portions 21 to accommodate the coiled springs 22 that bear against the upwardlyV extended flange 23 and downwardly ext-ended fiange4 24 respectively, to the end that ythe supporting blocks 19 are normally urged outwardly.'

Each of the supporting blocks 19 is formed with a cut out portion 24 formed lin its inner edge which openings are formed with circular portions to accommodate the heads 25 of the locking fingers 18 so th'att-he locking fingers'may swing within the cut out portions to accomplish the purpose of the locking fingers tobe hereinafter more fully described.

Communicating with the cut out portions 24 are bores 26 that are disposed at oblique angles with respect to the outer surfaces of the blocks 19 to permit an elongated tool to be inserted in the cut out portions 24 for engagement with the fingers 18 to move themy to their active positions. Coiled springs 27 are positioned around portions of the heads 25, the vends thereof beingin engagement with the fingers 18 to normally urge them to their inactive positions or out of contact with the groove 28 formed in the enlargement 13. y

The groove 28 is formed with a shoulder 29 that is adapted to be engaged by the upper edges of the fingers 18 to hold the rod 12 and jaws supported at the Alower end thereof, vto their inactive positions to allow the underreamer to be slid through the Well tubing or lining.

The lower end of the rod 12 is tapered at 30 andis adapted to operate Within the cut out portions 31 of the blades 32, the cut out `portions 31 being disposed at oblique angles with respect to the body portion, the lower walls ot' the cut out portions 31 being inclinedat 3l to present cam surfaces over `.which the tapered end 30. of the rod may ino/ve to force the blades outwardly.

l Threaded openings 33 areY provided in the ibodyportion" 6 `adjacent`^ to the lower end thereof, which openings accommodate the bearing members 3d that are .also formed with threaded vportions i These bearing members .34 extend into openings formed in the blades 32 and act as supports for the blades to allowtheblades to pivot within the body 'portion (i, under the kaction ot the rod 12. Itmight be fur-y ther stated that the upper ends of the blades `32 arecut awayat 36 providing clearances to allow the blades to swing in a manner as described. i.

In order that the blocks 19 maybe removably Asupported within the cnt out portions of the body portion 6, secnring plates 37 are provided .which securing plates engage the extensions 20 of the block to restrict outward movement ofthe block. Screws 38 exwithin the body portion. A .suitable tool is now positioned in the bores 26 and the locking lingers 18 pressed downwardly to engage the shoulder 2S) ofthe groove 2S lock- 4ing the rod 12 in its uppermost position, at

the saine time moving the blades 32 to their inactive positions.

`When the reamer reaches the end ol the well casing and the blocks 1!) thereof pass .through the end of the casing, the spring member 22 acts to move the blocks 1S) outwardly disconnect-ing the lingers, to the end that the blades drop downwardly and more to their .active positions.

After the reaming operation has been conipleted, an upward movementon the rod 12 will cause the blocks 19 to be moved m- :wardly and the ieamer withdrawn from the `well easing. It will be seen that an under-` reainei of `this character provides for the pivotal movement of the blades instead of a reciprocating movement thereof to the end that the blades will not become loosened from their support and fall into the we'll.

'l claim: f

` In an,` nnderreainer, a tubular body, said tublilai'body. having lateral openings, laterally movable blocks supported within the openings, coiled springs for normally moving the blocks outwardly, pivoted lingers carried by the blocks, a `vertically movable iod having` a groove defining a shoulder, movable within the body, said lingers adapted to engage the shoulder'to hold the rod in an elevated position, pivoted blades having enlargements attheircnds, said rod adapted to engage the enlargements to lock the lilades in their active positions, at `the end of the tubular member, and said blocks adapted to move laterally to disengage the fingers and shoulder, and means for returning the rod to its initial position.

In testimony that I claim the foregoing as my own, I havehereto affixed inysignature.

BENJAMlN FRANKLIN WALDRON.

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